Molding apparatus for forming a plurality of structural elements



United States Patent [72] inventor Derrel J. Ridenour 4646 E. Lewis Ave., Fresno, Calif. 93702 [21] App1.No. 777,997 [22] Filed Nov. 13, 1968 Continuation-in-part of Ser. No. 576,581, Sept. 1, 1966, abandoned. [45] Patented Nov. 24, 1970 [54] MOLDING APPARATUS FOR FORMING A PLURALITY OF STRUCTURAL ELEMENTS 11 Claims, 17 Drawing Figs.

{52] U.S. Cl 249/129, 25/121 M, 264/297 [51] Int. Cl B28b 7/24 [50] Field of Search 249/129,

119, ll8,139,120,160,l6l,163, 164,167; 264/297;25/121M Primary Examiner-J. Spencer Overholser Assistant Examiner-DeWalden W. Jones Attorney-Huebner & Worrel ABSTRACT: A molding apparatus for forming a plurality of elongated structural elements which provides a plurality of spaced partitions adapted to be rested upon a support surface and to receive a flowable hardenable material therebetween with the partitions having opposite ends individually including outwardly extended camming means and a partition lifting and element stripping frame circumscribing the partitions providing opposite end members having a plurality of openings therethrough for receiving said camming means of the partitions in sliding engagement to cause limited horizontal and vertical relative movement between the partitions and the end members automatically to release the structural elements from the forming apparatus after curing incident to raising of said end members from the support surface.

55 6 Q? 4/ 2 6R 6 l 1 5 Patented Nov. 24, 1970 3,542,329

Sheet 3 of 5 A TTORNEV DERRE'L J. R/DE/VOUR lNVENTOR 74 7 16, 6 MVM Patented Nov. 24, 1970 3,542,329

DERREL J. RIDENOUR Patented Nov. 24, 1970 I 3,542,329

Sheet 5 of 5 143 Q My 7 /42 l55 WWW 55 M FM A TTO/PNEKS MOLDING APPARATUS FOR FORMING A PLURALITY OF STRUCTURAL ELEMENTS CROSS REFERENCE TO RELATED APPLICATIONS The present application is a continuation-in-part of application Ser. No. 576,581 entitled A STRUCTURAL ELEMENT AND METHOD AND APPARATUS FOR MANUFAC- TURING", filed September 1, 1966, now abandoned.

BACKGROUND OF THE INVENTION The present invention generally relates to a molding apparatus for forming a plurality of elongated structural elements such as building wall sections, fencing walls, sidewalks, curb strips, parking lot bumper strips, and the like. Such elements are preferably constructed of a cast or stamped material, the former being characterized by concrete, cinders, ceramics, and plastics, and the latter by plastics, metal bonded cellulose and the like.

In the following application and description, reference will particularly be made to the formation of structural elements, as contemplated by the invention, which consists of precast concrete elements, although it is to be understood that his terminology encompasses any material which can be utilized in accordance with the teachings of the invention, and the invention and application are to be construed as including any similarly useful materials formable into structural elements having desired dimensions and configurations.

In recent years, substantial advancements have been made in the construction of walls for buildings, fences, fence posts, sidewalks, curb strips, parking lot bumper strips, and the like from concrete. In the past, such structural elements have been constructed on the job by the use of disposable forms custom made for each particular job. Single element forms are conventionally employed which must be tediously assembled prior to each use and similarly disassembled in order to remove the finished element after curing. On relatively large jobs requiring a great number of the structural elements, the single forms are not economically feasible in view of the time involved in their utilization and the labor costs. Attempts have previously been made to provide multiple element forms without success. The primary problem in casting a plurality of such structural elements in a single form is encountered during the removal of the elements from the forms after curing without damage to the elements or to the forms. Many structures of the prior art provide complicated and troublesome form expanding mechanisms which are expensive and difficult to operate. These forms are customarily utilized in a horizontal position which seriously restricts the number of elements that can be cast during any one pouring. Such forms are usually employed in a horizontal position in order to provide a relatively shallow pouring depth corresponding to the width of the curb strip, bumper strip or the like which, of course, precludes the pouring of such structural elements in stacks having a plurality of layers. Accordingly, they can only be constructed in a single horizontal layer requiring a relatively large pouring area not usually available at the job site or in the pouring yards of manufacturers of such structural elements.

SUMMARY OF THE INVENTION Accordingly, it is'an object of the present invention to provide an improved molding apparatus for forming a plurality of structural elements.

Another object is to provide such an improved molding apparatus which enables structural elements such as curb strips, bumper strips and the like to be economically produced in suf ficiently large quantities to permit storing for subsequent use as needed.

Another object is to provide an improved molding apparatus ofthe character described which is capable of forming such a plurality of elongated concrete structural elements in a single pouring operation.

Another object is to provide a molding apparatus which disposes the elongated structural elements in a vertical attitude so that a maximum number of such elements can be formed in a minimum ofspace.

Another object is to provide a molding apparatus which automatically dependably releases the structural elements after curing for substantially unrestricted removal from the molding apparatus with virtually no damage to the elements or to the forming apparatus.

Another object is to provide a molding apparatus for forming a plurality of structural elements which utilizes a plurality of element forming chambers that-are automatically opened and closed by a compound movement of the chambers in both a horizontal and a vertical direction relative to each other completely to release the structural elements after curing.

Another object is to provide a molding apparatus for forming a plurality of structural elements which is automatically returnable to a condition for immediate reuse.

Other objects and advantages of the present invention will subsequently become more clearly apparent upon reference to the following description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view ofa molding apparatus embodying the principles of the present invention used to form a plurality of elongated concrete elements.

FIG. 2 is a partial cross-sectional view, taken on line 22 of FIG. 1.

FIG. 3 is a partial cross-sectional view showing the same portion of the molding apparatus as shown in FIG. 2, but with the molding apparatus in an unclamped condition.

FIG. 4 is a partial section, taken on line 4-4 of FIG. 1.

FIG. 5 is a partial section showing the same portion of the molding apparatus as shown in FIG. 4, but with the molding apparatus in an unclamped condition.

FIG. 6 is a partial cross section, taken on line 6-6 of FIG. 1.

FIG. 7 is a partial cross section showing the same portion of the molding apparatus as shown in FIG. 6 but with the molding apparatus in an unclamped condition and raised to effectuate release of the cast concrete elements.

FIG. 8 is a perspective view of reinforcing steel used in the concrete element.

FIG. 9 is a somewhat enlarged fragmentary end elevation of the molding apparatus showing one of a plurality of camming slots utilized to aid in removing the concrete elements from the mold. I

FIG. 10 is a perspective view of a second form of molding apparatus embodying the principles of the present invention,

shown in an assembled pouring position.

FIG. 11 is a somewhat enlarged end elevation of the molding apparatus of FIG. 10.

FIG. 12 is a top plan view of the molding apparatus of the second form.

FIG. 13 is a second form.

FIG. 14 is a fragmentary plan view of one of the element forming partitions within the molding apparatus disposed in its free arcuately curved form prior to assembly into the molding apparatus.

FIG. 15 is a somewhat enlarged fragmentary top plan view of one of the element forming chambers of the partition of FIG. 14.

FIG. 16 is a somewhat enlarged fragmentary end elevation showing the outer frame of the molding apparatus raised to an element stripping position. A

FIG. 17 is a somewhat enlarged fragmentary transverse vertical section through the stripping frame, taken generally along the line I7-17 of FIG. 16.

side elevation of the molding apparatus of the DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more particularly to the drawings, a molding apparatus 35 embodying the principles of the present invention is utilized to produce a plurality of concrete structural elements of a type employed in fence wall construction. The

elements to be formed simultaneously in the mold and have an external rectangular flange 40 about their periphery.

the concrete elements, divider. plates 42 are disposed in the molding apparatus 35 inside the frame 36. The divider plates 42 have surfaces 43 which correspond to the sides of the concrete elements and have identical corrugations therein, as best shown in FIGS. 4 and 5. The divider plates 42 are positioned substantially parallel to the side plates 38 and extend between the end plates 37. In order to provide the proper contour for the concrete elements formed in the outermost chambers 41, the inside surfaces of the side plates 38 are provided with contour plates 44. These contour plates also correspond to the corrugations in the sides ofconcrete elements.

To assist in removal of concrete elements cast in the molding apparatus 35 after they have set, the divider plates are tapered downwardly so that the top portion is wider than the bottom portion. This is best shown in FIGS. 6 and 7. This taper is conveniently provided in this preferred embodiment by forming the divider plates 42.0f two separate sheets of steel which are welded together at their bottom and are joined through a steel separating rod 45 at their tops.

In order to join the divider plates 42 to the frame 36 of the molding apparatus 35. upper ears 47 and lower ears 48 are formed at each ear of the divider plates 42 and extend outwardly therefrom. Upper ears 47 and lower ears 48 are also provided on the side plates 38 to join them to the end plates 37. The end plates 37 have upper slots 49 and lower slots 50 disposed in alinement with the upper ears 47 and lower cars 48 on the divider plates 42 and side plates 38. The upper ears 47 and lower ears 48 have keyholes 51 through their outer portion-After the upper ears 47 and lower ears 48have been inserted in the upper slots 49 and lower slots 50 of the end plates 37, key rods 53 are inserted in the keyholes 51 and fixed therein. The key rods prevent the upper ears .7 and lower ears 48 from being removed from the upper slots 49 and lower slots 50 in the manner common to mechanical construction art.

Connected in this manner, the side plates 38 and divider plates 42 cannot be disassembled from the end plates 37, however, they can move a limited distance with respect to the end plates 37 in both a longitudinal and lateral direction. Furthermore, the upper slots 49 and lower slots 50 are formed of such shape with respect to the upper ears 47 and lower cars 48 that up and down movement between the side plates 38 and divider plates 42, and the end plates 37 is possible, while the molding apparatus 35 is loosely assembled by means of the key rod connections of the upper ears 47 and lower ears 48 in the upper slots 49 and lower slots 50.

Assembled in this manner, the molding apparatus 35 allows considerable relative movement between the end plates 37, side plates 38 and divider plates 42. This movement is important in releasing cast concrete elements from the molding apparatus as will be later explained.

To fix the molding apparatus 35 so that relative movement between the end plates 37, side plates 38 and divider plates 42 is prevented, hand clamps 55 are utilized. The hand clamps 55 are first placed at each corner of the frame 36 and engage the clamp together flanges 39 on the side plates 38 and flanges 40 on the end plates 37, as best shown in FIG. 1. This clamping action forces the upper cars 47 and lower wears 48 into the upper slots 49 and lower slots 50 to provide accurate position ing of the end plates 37, side plates 38, and divider plates 42 relative to each other upon clamping of the mold as aforesaid. To effect this accurate positioning of upper ears 47 and lower ears 48 in upper slots 49 and lower slots 50, vertical alinement earns 57 are provided on both upper ears 47 and lower ears 48.

The vertical alinement earns 57 consist of cam surfaces 61 on the lower edges of upper ears 47 and lower cars 48 which extend the full distance of the ears and are disposed outwardly and upwardly. These cam surfaces ride on the lower edge of the upper slots 49 and lower slots 50 as the upper ears 47 and lower ears 48 are forced into those slots and raise the side plates 38 and divider plates 42 against the'force ofgravity into proper vertical alinement with the end plates 37 upon clamping ofthe mold as aforesaid, as best shown in FIGS. 2 and 3.

To provide proper horizontal alinement upper slots 49 and lower slots 50 are triangular in shape, being considerably wider at their lower portions than at their upper portions. This provides two horizontal alinement cam surfaces 59 and 60 on the sides of each of the upper slots 49 and lower slots 50 which are directed upwardly and inwardly. Thus, as the upper cars 47 and lower ears 48 are forced into the upper slots 49 and lower slots 50 by the clamping of the mold as heretofore explained, the vertical alinement earns 57 force the ears upwardly in the slots, and the horizontal alinement cam surfaces 59 and 60 center the ears horizontally in the slots.

To prevent any leakage of concrete through the upper slots 49 and lower slots 50 during pouring, gaskets 58 are provided which fit snugly over the upper cars 47 and the lower ears 48 and are disposed on the ends of the divider plates 42 adjacent to each row of upper slots 49 and lower slots 50. Thus, when the mold is clamped, the gaskets 58 seal the chambers 41 from the slots.

After the mold is clamped at the'corners of frame 36, the divider plates 42 are further alined at their intermediate por tions by lateral alinement bar 62. As best shown in FIG. 6, the lateral alinement bar 62 has recesses 63 provided in its lower edge which correspond to the proper spacing of divider plates 42 at their intermediate portions. The recesses 63 have downwardly and outwardly tapering edges which position the divider plates 42 as the lateral alinement bar is forced downwardly upon the divider plates. The lateral alinement bar 62 has angle flanges 65 at each end which are secured to angle iron 66 on the upper edges of the side plates 48, as best shown in FIGS. 1 and 6, to secure the lateral alinement bar in place. Clamps 55 are also used for this purpose. I

After the molding apparatus 35 has been clamped and all the parts thereof properly alined it is secured to a pallet 67 i which forms a bottom to the chambers41. The securing of the molding apparatus 35 to the pallet 67 is accomplished by placing an angle iron 68 laterally beneath the pallet 67 and clamping the end extensions of the angle iron to a longitudinally disposed angle iron secured to the lower edge of the side plates 38 by means of clamps 55, as best shown in FIG. 1.

The molding apparatus 35 and pallet 67, thus assembled, are then preferably placed on a vibrating table of the type commonly used in the art of concrete casting. The vibrating table is then actuated and concrete 71 is poured into the top of the molding apparatus 35, as best shown in FIG. 1. As well known. in the concrete casting art, the vibrating table assures proper settling of the concrete 71 into the chambers 41 of the molding apparatus and obviates the formation of voids in the concrete as it'fills the chambers 41. When the chambers 41. are filled, the excessive concrete is screeded at the top of molding apparatus to provide a finished surface.

Where steel reinforcement of the concrete elements is considered necessary for adequate strength, as in this embodiment, sections of steel mesh are preformed to the corrugated contour of the chambers 41 and are inserted in the chambers prior to pouring of the concrete and subsequent to the clamping of the mold. The steel mesh 73 is formed with oppositely and outwardly extending legs 74 which engage the side walls molding apparatus 35 is moved with the pallet 67 in a steam treating area where the concrete is cured by steaming it for approximately twelve hours at approximately 150F. This initial curing provides adequate strength and set to the concrete to permit removal of the concrete elements from the molding apparatus.

To accomplish removal of the concrete elements from the molding apparatus 35, the mold is first released from the pallet 67 by releasing clamps 55 which hold the lateral angle iron member disposed beneath the pallet to the longitudinal angle iron formed on the lower edge of the side plates 38. The mold is then unclamped at the corners of frame 36 and the lateral alinement bar is unclamped and removed from the top of the mold. The mold is then lifted a short distance above the pallet 67iby means of a lifting saddle. The lifting saddle consists of two chains 76 each connected to the ends of one of the end plates 37 which are in turn interconnected at their center points by a T-member 77 disposed longitudinally over the center of the molding apparatus 35. A lifting chain 78 is loose- Iy connected between the ends of the T-member 77 and is engageable with a crane book, as best shown in FIG. I.

As the molding apparatus 35 is lifted above the pallet 67, the upper ears 47 and lower ears 48 slip downwardly and inwardly with respect to the upper slots 49 and lower slots 50 and allow relative movement between the divider plates 42 and side plates 38 andthe end plates 37, as previously explained. This allowance of relative movement plus the vertical taper on the divider plates 42, previously described, permit the concrete elements to drop downwardly with respect to the molding apparatus by force of gravity. Since the molding apparatus is only raised a short distance above the pallet 67, the downwardly dropping concrete elements fall back onto the surface of the pallet, as best shown in FIG. 7. When all of the concrete elements have been freed, the molding apparatus is raised further by means of the lifting saddle and crane and is separated completely from the concrete elements which remain on the pallet 67.

After the molding apparatus 35 has been removed from the concrete elements, they are secured to the pallet 67 by means of wire or steel bands and are stored for further curing. When the elements have adequately cured for use, they are forklifted on the pallet 67 onto a truck and transported to the job site. At the job site the concrete elements are released from the pallet by breaking the securing means and are set in place in a concrete wall structure.

Release of the concrete elements from the molding apparatus 35 after casting can be further assisted by treating the mold surfaces with form oil or etching compound before pouring of the concrete into the chambers. This technique is well known in the concrete casting art. It should also be understood, of course, that any special surface desired may be provided on the concrete elements.

As an alternate method of removing the concrete elements from the molding apparatus 35, it has also been found quite feasible to raise the molding apparatus and concrete elements off of the pallet 67 and set them on the forks of a forklift truck. The molding apparatus is then unclamped and the elements dropped onto the forks in the same manner just described. After they have been freed from the molding apparatus the concrete elements are banded together with steel wire or some other suitable means and are transported to storage or loaded on a truck for delivery to ajob site, as desired.

From this description of the present invention, it will be understood that the concrete elements may be formed with corparatus, but they can beeconomically handled during manufacture, transportation to the job site. and installation.

SECOND FORM A second form of molding apparatus embodying the princi ples of the present invention is shown in FIGS. 10 through 17. This form of molding apparatus is generally indicated by the reference numeral 135 and is particularly intended for forming a substantially greater number of elongated structural elements which are to be employed as parking lot bumper strips or the like. The molding apparatus has an open top I36 and bottom 137, opposite ends 138 and opposite front and back rugations in one side only with the other side flat. In forming walls for buildings from the concrete elements, this form of the elements is generally preferred over the form disclosed above with both sides having corrugations. The molding apparatus 35 described above can be readily used for forming this alternate embodiment of the concrete element by minor modification. Not only can the concrete elements be produced off the site in substantial quantities because of the plurality of elements produced by the single molding apsides 140 and 141, respectively.

A plurality of divider plates or element forming partitions 142 are disposed within the molding apparatus 135 in substantially upright attitude and in horizontally spaced substantiaily parallel relation to each other. The partitions are constructed of a substantially rigid sheet metal material having opposite ends 143 and opposite top and bottom edges I-i-t and H5. respectively. Although substantially rigid, the partitions are sufficiently flexible to permit arcuate bending movement between their ends and are preformed in a somewhat bowed configuration, as best shown in FIG. 14.

The partitions 142 further include a substantially smooth backside 147 and an opposite front side 148. A plurality of elongated divider panels 150 are laterally outwardly extended from the front side of the partition in horizontally substantially equally spaced relation to form a plurality of elongated element forming chambers 152. Each of the divider panels is fabricated to include a fillet p0rtion'153 in angularly disposed relation between the panel and the front side of the partition. As best shown in FIG..12, with the partitions disposed in their horizontally spaced, relation, the backside 147 of each partition provides a closure wall engaging the outer edges of the adjacent panels for each ofthe chambers 152. With particular reference to FIG. 14, the bowing of the partition I42 disposes the outer edges of theadjacent divider panels in maximum spaced relation to each other. A pair of camming ears are outwardly extended from each end 143 of the partitions 142 individually in closely spaced relation to the top and bottom edges thereof. Each of the camming ears provides a lower ramp or camming portion 157 and a circular bore 158 therethrough.

A substantially rectangular partition lifting and element stripping frame, generally indicated by the reference numeral 160, is disposed in circumscribing relation to the partitions 142. The. frame includes opposite end members I62 constructed of oppositely spaced substantially parallel upright angle iron side members 163 which are rigidly interconnected at their ends by similar angle iron top and bottom members 165 and 166. Upper and lower panels 168 and 169, respectively, are disposed in interconnecting relation between the side members respectively adjacent to the top and bottom members.

As best shown in FIGS. 10, 11 and 16,21 plurality oflost motion or camming slots are formed through the upper and lower panels 168 and 169 in horizontally spaced relation corresponding to the spacing of the camming ears 155 on the partitions 142. Each of the camming slots is constructed in the form ofa parallelogram and provides opposite inner and outer spaced substantially parallel side edges 177 and 178, respectively, and upper and lower angularly downwardly sloped edges 180 and 181, respectively. It will be noted that the centermost slot is only slightly larger in width in the plane of the panel than its corresponding centermost camming ear 155 of the partitions. The outwardly adjacent slots on each side of the centermost slot are of a width corresponding to the width of two of the camming ears with each successive slot increasing another width of an ear progressively outwardly toward the side members 163 ofthe frame.

An elongated locking rod is extended through the bores 158 in the camming ears I55 outwardly of the upper and lower panels 168 and 169 and provides opposite ends 186 which terminate short of the side members 163 of the frame. Accordingly, the end members 162 of the frame are permitted limited travel toward and away from the opposite ends 143 of the partitions 142 by the extension of the camming ears 155 through the camming slots 175. A plurality of masking plates 188 are secured to the side members 163 of the frame, as by welding or the like, so as to preclude inadvertent axial removal of the locking rod from the ears during all positions of the frame relative to the ears. A pair of lift hook rings 190 are mounted on the side members adjacent to the top members 165 of the frame.

A partition clamping cover 192 of substantially the same size as the partitions 142 is disposed at the front side 140 of the molding apparatus 135. The clamping cover has a plurality of vertically disposed horizontally spaced substantially parallel stiffener strips 194 secured to the outer surface thereof, as by welding or the like, in substantially alined relation with the divider panels 150 of the partitions. The clamping cover includes opposite ends 195 and camming ears 196 identical to the ears of the partitions. Pairs of upper and lower bolting strips 200 are secured across. the two inwardmost stiffener strips 194 inwardly extended relation from the opposite ends 195 of the cover An elongated arcuately curved strongback clamping bar 205 is disposed on the stiffener strips 194 of the clamping cover 192 intermediate the upper and lower bolting strips 200. The clamping bar is rigidly braced by an outwardly extended handle rod 206 and intermediate braces 207. A plurality of similarly arcuately curve-d backing bars 210 are disposed against the backside 14-7 of the rearwardmost partition 142 and include outwardly extended bolting strip ends 212. A plurality of elongated tightening bolts 215 are extended through the bolting strips Z'il i) and the clamping bar 205 for screwthreaded engagement with their corresponding backing bars 210. Each of the tightening bolts includes a T-head 216 for manipulation of the bolts to draw the partitions tightly together in their pouring position of FIG. 12. A plurality of hole forming rods for the structural elements having outer T- ends 221 are extended through corresponding bores in the partitions 142 in spaced upper and lower rows adjacent to the top and bottom edges 144 and 145 thereof.

The partitions 142 are initially disposed in their relaxed condition of FIG. 14 bowed forwardly toward the front side 140 of the molding apparatus 13-5. After assembly of the partition clamping bar 205, the tightening bolts 215 are inserted in the described manner and manipulated to draw the partitions in closely tightly held relation to each other in conforming relation to the clamping bar and backing bars 210. This places a reverse bow in each ofthe partitions which draws the divider panels 150 of the element forming chambers 152 toward each other in minimum spaced relation precisely to form the structural elements in the desired configurations ln such condition, the camming ears 155 are fully extended through the camming slots 175, as best shown in FIG. 13. As noted, axial displacement ofthe locking rod 185 is precluded by the masking plates 188.

With the molding apparatus in such tightly clamped condition, it is disposed upon a somewhat enlarged rectangular pad or mat 225 of resilient material such as rubber or the like for supporting the apparatus on a vibrating table such as that previously described in the operation of the first form of the present invention. Concrete or other suitable flowable hardenable material is then poured into the top 136 of the molding apparatus. The material is permitted to gravitate downwardly through the element forming chambers 152 between the partitions 142 and around the hole forming rods 220. After the pouring operation has been completed, the molding apparatus may be moved to a material hardening area, as before described.

After hardening, the clamping bar 205 and backing bars 210 are removed by withdrawing the tightening bolts 156 therefrom. The lifting saddle employed in the first form of the present invention is then utilized by connecting the lift chains thereof to the hook rings 190 onthe end members 162 the stripping frame 160. Theend members are elevated a short distance relative to the partitions by way of the camming slots 175. During, such movement, the lower edges 17% of the camming slots slide outwardly along the lower cumming ramp 157 of the camming ears 155 to space the end members 262 outwardly from the opposite ends 143 of the partitions 142.. Such outward movement continues until the upper and lower panels 168 and 169 of the end members abut their respective locking rods 185 in the outer ends ofthe camming ears.

At the'same time that the lower edges 17% of the cumming slots are sliding-along the lower ramp portion 157 of the camming earsll55. a concurrent lateral horizontal shifting movement occurs between the individualpartitions M2. Such lateral shifting movement causes the ears to slide laterally against the opposite or outer side edge R78 of the camming slots, as shown in FlG. 16. so that each partition and element chamber 152 -is separated a distance corresponding to the width of the ears. As previously noted, the camming slots outwardly from the centermost slot are of a progressively width in order to accommodate theincreased cli outermost camming ear must move in order-to b its adjacent partition.

Upon such separation of the adjacent partitions K42 and element containing chambers 152. and the endward disposition of the end members 162 of the frame. the partitions are relatively free to return to their normally relaxed forwardly bowed condition of FIG. 14. This movement permits the divider panels 150 to move a slight amount away from each other in order effectively to open the chambers to permit free gravitational descent of the structural elements formed therein downwardly upon the resilient pad 225 of the support surface. Such automatic opening of the element containing chambers occurs almost simultaneously with the raising of the partitions from the support surface so that the elements must drop only a minimum distance.

The raising of the partitions 142 is, ofcoursc. delayed by the relative movement permitted by the camrning slots 175 which effect the described separation of the end members 162 of the frame 160 from the partitions and the physical separation of the partitions from each other. The partitions and stripping frame are then further raised in stripping relation to the structural elements which remain uponthe support surface. Frior to complete removal of the partitions and stripping frame, a suitable banding member is placed around the plurality of structural elements to maintain them in assembly for subsequent handling and storing. The partitions and stripping frame are then completely removed and may be immediately "reused for a subsequentmolding operation by resetting upon a backing bars 210.

Although. the invention has been herein shown and described in what are conceived to be the most practical and preferred embodiments, it is recognized that departures may bemade therefrom within the scope of the invention, which is 4 all equivalent devices and apparatus.

Iclaim:

1. A molding apparatus for forming a plurality of structural elements comprising a plurality of partitions forming a plurali ty of substantially vertically disposed horizontally spaced open chambers with the partitions being adapted to be rested upon a support surface forming a lower closure for the upwardly opening chambers so as to confine therein a suitable flowable hardenable material, a substantially rectangular frame circumscribing the partitions providing wall portions having a plurality of lost motion slots formed therethrough, element release means including ears on said partitions individually movably disposed in said lost motion slots for interconnecting said partitions when disposed upon said support surface but pen mitting limited vertical and horizontal movement between them incident to raising said partitions off of said support surface.

2. The molding apparatus of claim 1 including lock means extended through said ears.

3. The molding apparatus of claim 2 in which said slots provide predetermined upper portions of substantially the same width as the ears measured in the plane of the wall portions and lower portions tapered downwardly and outwardly from said upper portions to a width substantially greater than the width of said ears, said ears having a lower upwardly and outwardly slanted cam surface for sliding engagement with the lower portions of the slots, and said lock means providing a stop for limiting complete separation of said ears and said wall portions of the frame.

4. The molding apparatus of claim 3 including gaskets fitted about the ears for engagement with said wall portions of the frame in covering relation to the slots when the apparatus is rested upon said support surface.

5. A molding apparatus for forming a plurality of structural elements comprising a plurality of vertically disposed horizontally spaced partitions adapted to be rested upon a support surface and to receive a flowable hardenable structural material therebetween and having opposite ends individually proving outwardly extended camming means, and a partition lifting and element stripping frame circumscribing the partitions and providing opposite end members having a plurality of slits therethrough for receiving said camming means of the partitions with the slots including ramp portions slidably engageable by said camming means simultaneously to cause limited horizontal and vertical movement between the partitions incident to raising said end members of the frame from said support surface in order freely to strip the partitions from the structural elements.

6. The molding apparatus of claim 5 in which said slots provide spaced substantially parallel vertically disposed side edges and spaced substantially parallel upper and lower edges angularly related to theside edges in parallelogram form, and said camming means on the partitions comprising elongated ears having lower angularly upwardly and outwardly sloped edges with the ears initially disposed adjacent to one side edge of the slots and adjacent to said upper edge thereof and during said raising of the end members of the frame said lower edges of the ears slidably engaging said lower edges of the slots to move the ears and their respective partitions substantially horizontally toward the opposite side edges of the slots with said ears concurrently camming the end members inwardly outwardly from the partitions as the end members are raised vertically relative to the partitions.

7. The molding apparatus of claim 6 in which the centermost slot in the end member is of a width measured in the plane of the end member substantially corresponding to the width of its associated ear with each successively spaced slot on each side thereof being progressively greater in width an amount equal to an ear width in order that all the partitions are separated horizontally from their adjacent partitions the width ofone ear during said raising of the end members of the frame.

8. The molding apparatus of claim 7 in which said ears include alined bores, and an elongated locking rod extended through the bores outwardly adjacent to said end members to limit inward travel of the end members from the partitions so as to preclude their complete separation.

9. The molding apparatus of claim 8 including a pad of resilient material interposed said support surface and the partitions to provide a cushion for the structural elements during their removal incident to-raising the partitions and frame.

10. The molding apparatus of claim 9 in which each partition provides a plurality of laterally extended divider panels forming a plurality of elongated vertically disposed element forrriing chambers between their ends.

11. The molding apparatus of claim 10 in which said partitions are prebowed in arcuately curved relation from an upri ht plane passin through their ends so as to dispose the pane s in a spread sti bstantially open position, and a plurality of arcuately curved side bars releasably mounted between the end members of the frame for engagement with the partitions to reverse bend them in arcuately conforming relation to the bars as as to move the panels toward a closed position during the curing of said elements within the chambers with the panels automatically returning to their open positions upon removal of said side bars from the partitions. 

